1. Field of the Invention
The present invention relates to serial line printers of the type using insertable drop-on-demand ink jet print/cartridges and more particularly to constructions for such printers that enable high speed throughput with automatic feeding of successive print sheets.
2. Background Art
U.S. Pat. No. 4,709,245 describes highly useful printer configurations wherein a plurality of insertable print/cartridges, e.g. of the thermal drop-on-demand type, are accurately positioned, optically detected and synchronized in drop ejection to produce proper interplacements of drops in the common printing of a line. Thus a common carriage traverses each of its supported print/cartridges across the entire print. This printer approach is highly desirable for producing outputs comprising different ink types, for enhanced resolution (see U.S. Pat. No. 4,709,247 and for some enhancements in regard to output speed.
U.S. application Ser. No. 20,416, entitled "Compact Printer Having An Integral Cut-Sheet Feeder" by Piatt and filed concurrently herewith discloses a unique configuration for providing a line printer with a sheet feeding capability in a compact, integral unit. This is accomplished, in part, by utilizing the print platen both to feed successive sheets from an integral supply station and to transport the fed sheets through the print zone and out of the printer unit. One preferred embodiment of the printer/feeder unit divides the transport drive for sheets between an upstream transmission zone at the sheet supply station and a downstream transmission zone, where a pressure roller presses passing sheet portions against the rotating print platen. This approach utilizes guide structure for directing the leading edge of a fed print sheet to the pressure roller nip.